Currently, the collimation of exiting light rays from a backlight module is mainly achieved by lenses provided in the exiting direction to the backlight module. For example, a point light source 001 is provided at the focal plane, and light rays emerging therefrom such as the light ray α (as shown in FIG. 1) arrive at the lens 002 and are collimated by the lens, and in turn exit perpendicular to the exiting surface of the backlight module.
With the current collimation, however, the lenses can have collimating function for only the light rays from the point light sources at their focal planes, but not for the light rays from other point light sources such as the light β as shown in FIG. 1, resulting in a poor collimation effect for the exiting light rays as a whole from the backlight module.
It should be noted that the information disclosed in the above BACKGROUND section is only to enhance understanding of the background of the disclosure, and thus may contain information which is not part of the prior art known to those skilled in the art.